The voice quality of a mobile telephone is acceptable when on the road but it is not currently up to the same standard as that of a wired line telephone. Additionally, there is no charge for answering telephone calls on a wired line telephone whereas there is often a charge for answering incoming calls on a mobile telephone. For these reasons, subscribers may prefer to that incoming calls to their mobile telephones be received on their wired line telephone if they are at home. Conversely, subscribers may prefer to receive calls to their wired line telephone on their mobile telephone if they are away from home.